1. Field of the Invention
The present invention relates to equipment for cellular wireless communications with mobile phones or the like and, more particularly, to functionality of deactivating communication using a mobile phone in public places where such communication would be annoyance to others around the user of the mobile phone.
Moreover, the present invention relates to equipment for cellular wireless communications with mobile phones or the like and, more particularly, repeaters or base stations for wireless communications to enhance the quality of the wireless communications.
2. Description of Related Art
Inside public transports such as trains and buses and public places such as restaurants and theaters, where many people, strangers often gather in a limited space, the use of a mobile terminal such as a mobile phone may cause trouble when one who does not want others using a mobile phone around him or her and one who wants to use his or her mobile phone happen to be there. Particularly, for a person who wears an electronic medical device for life-support purposes, there is a possibility of the medial device being affected by radio waves sent from an operating mobile terminal around that person and the use of a mobile terminal very close to that person is a critical problem. Even for people who do not need such medical device, a nearby mobile phone talker maybe a nuisance. Therefore, the use of mobile terminals is often banned in public transports and places.
However, as long as banning the use of mobile terminals in specific places cannot be effected by physical force and is a public rule, there are, in actuality, bad-mannered mobile terminal users who ignore such rule. To effect this rule and make public transports and places more comfortable for people, it is thus necessary to make mobile phones physically impossible to perform communications in specific places.
As prior art methods for making a mobile terminal impossible to perform communications in specific places, a number of diverse methods have been disclosed in JP-A No. 178054/1999, JP-A No. 268636/2001, JP-A No. 86566/2001, JP-A No. 218264, JP-A No. 78264/2001, JP-A No. 44918/2001, JP-A No. 257772/2001, JP-A No. 285952/2001, and JP-A No. 41282.
Among them, the method disclosed in JP-A No. 178054/1999 is outlined below. Radio waves of the same frequency as the radio waves that are transmitted on a downlink radio communications channel from a base station to a mobile terminal are emitted in a specific place to interfere with the radio waves on the downlink radio channel received by the mobile terminal, thus making the mobile terminal impossible to perform communications. The method disclosed in JP-A No. 86566/2001 is outlined below. A pseudo base station is installed to send radio waves similar to radio waves on a downlink radio channel sent from a base station. When a mobile terminal comes near the pseudo base station, it is handed over to the pseudo base station so that the communication between the mobile terminal and the real base station is made impossible.
In other methods disclosed in the remaining above-mentioned patent applications, a mobile terminal is provided with specific functionality that makes it impossible to perform communications in specific places and the aim is attained by using such functionality.
With any of the above methods, the goal of making a mobile terminal impossible to perform communications in specific places can be achieved.
In the method disclosed in JP-A No. 178054/1999, radio waves interfering with the downlink radio channel from the base station make the mobile terminal impossible to receive the downlink channel. To effect this, radio waves stronger than the radio waves transmitted on the downlink radio channel from the base station must be emitted to be received by the mobile terminal. In particular, CDMA, which is expected to be popular in the future, allows for spread spectrum communications in which the effect of radio wave interference is alleviated by widespread spectrum. To bring about radio wave interference with the downlink radio channel in the CDMA communications, radio waves considerably stronger than those transmitted on the downlink radio channel from the base station must be emitted to be received by the mobile terminal. On the contrary, there would be a risk that such strong radio waves affect medical devices or the like.
The method disclosed in JP-A No. 86566/2001 is to hand over a mobile terminal to a specially installed pseudo base station. Some standards of CDMA which are now commonly used, for example, TIA/EIA/IS-95 whose standard specifications were released on May 18, 1995 and ARIB-STD-T63 whose standard specifications were released on January, 2000, prescribe the following. When a mobile terminal catches radio waves emitted by a new base station and finds that a handover to the new base station is possible, the mobile terminal sends an uplink signal message that the new base station exists to the base station to which it was connecting. After it is verified that the newly found base station can be used by the mobile terminal from the response signal from the base station, the handover is executed. Therefore, a handover to a pseudo base station not recognized by a telecommunications service provider (hereinafter, referred to as a telephone company) does not occur.
To effect the method disclosed in JP-A No. 86566/2001 for mobile terminals pursuant to the above standards, cooperation of telephone companies that operate communications systems must be obtained to make arrangements for using the pseudo base station. However, if some telephone company that does not introduce pseudo base station equipment exists, whereas other telephone companies do so, only the communications system operated by the former telephone company can be used by mobile terminals in specific places. In consequence, the telephone companies that introduce such equipment suffer a loss. For other methods disclosed in other patent applications mentioned above, a special function must be added to mobile terminals. Therefore, to effect these methods, arrangements for such function must be made by the telephone companies that operate communications systems.